
/****************************************************************************
**
** Copyright (C) 2004-2008 VATATA.com . All rights reserved.
**
** This file is the part of the Miniutil Poject of VATATA.com.
** Vatata's miniutil library is lightweight and portable (for linux
** and Windows). The C++ Class Library included Threadpool, Dll danymic loading, 
** General socket application model and tcp server, httpserver/servlet, etc. 
** It is a pratical utility disigned for who don't want learn the Big C++ 
** Developing Platform, such as  Boost or ACE.
**
** This file may be used under the terms of the GNU General Public
** License versions 2.0 or 3.0 as published by the Free Software
** Foundation and appearing in the files LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file.  Alternatively you may (at
** your option) use any later version of the GNU General Public
** License if such license has been publicly approved by VATATA.com.
** (or its successors, if any) and the Miniutil Project Aministrators. 
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
** http://www.gnu.org/licenses/lgpl.html. If you are unsure which 
** license is appropriate for your use, please review the following 
** information: http://code.google.com/p/miniutil/ or contact 
** http://www.vatata.com.
**
** In addition, as a special exception, VATATA.com, as the sole
** copyright holder for Miniutil Project, grants users of VATATA
** P2P Platform the right to release and package with the related 
** libraries without the source code.
**
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. vatata reserves all rights not expressly
** granted herein.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/



/*


 pool.h
 implement a simple object pointer pool.

*/

#ifndef  __MINIUTIL__DATA__POOL___H
#define __MINIUTIL__DATA__POOL___H

#include <deque>

namespace miniutil
{
	namespace data
	{

		template<class T>
		class pool_ptr
		{
		protected:
			friend class pool<T>;

			T* _ptr;
			const std::deque<T*> & _pool;
            bool release_flag ;
			inline pool_ptr( T *_p, std::deque<T*> the_pool) : _ptr(_p), _pool(the_pool), release_flag(false)
			{}

		public:
			inline pool_ptr( const pool_ptr &p ) : _ptr(p._ptr), _pool(p._pool), release_flag(false)
			{
			}

			inline ~pool_ptr()
			{
                if (  _ptr == NULL )
                    return;

                if ( release_flag == false )
    				_pool.push_back( _ptr );
                else 
                    delete _ptr;
			}

			inline T&   operator*()  
			{  
			  return   *_ptr ;  
			}  
			inline const   T&   operator*()   const  
			{  
			  return   *_ptr ;  
			}  

			inline T*   operator->()  
			{  
			  return   _ptr ;  
			}  
			const   T*   operator->()   const  
			{  
			  return   _ptr ;  
			}
			inline T * get()
			{
				return _ptr;
			}

            inline void release()
            {
                release_flag = true;
            }
		};

		template<class T>
		class pool
		{
		protected:
			typedef pool_ptr<T> elementType;
			std::deque<T*> _pool;

		public:
			inline pool()
			{}

			inline ~pool()
			{
				while( _pool.size() > 0 )
				{
					T * p = _pool.front();
                    _pool.pop_front();
					delete p;
				}
			}

			inline elementType get()
			{
				T * p;
                if ( _pool.size() > 0 )
                {
                    p = _pool.front();
                    _pool.pop_front();
                }
                else
                    p = new T;
				return elementType(p, _pool );
			}
		};



//end miniutil::data
	}
}

#endif
